Machine tool for dressing articles on nonparallel surfaces



Sept. 15, 1931. R. DYAS ET AL MACHINE TOOL FOR DRESSING ARTICLES ON NONPARALLEL SURFACES 4 Sheets-Sheet l Filed July 13, 1928 and aar/'c7565 MACHINE TOOL FOR DRESSING ARTICLES ON NONPARALLEL SURFACES Filed July 13, 1928 i 4 Sheets-Sheet 2 Sept. 15, 1931. R. l.. DYs ET AL 1,823,824

MACHINE TOOL FOR DRESSING ARTICLES ON NONPARALLEL SURFACES Filed July 13. 1928 4 Sheets-Sheet l5 Sept. 15, 1931. R. DYAs ET AL 1,323,824

I MACHINE TOOL FIOR DRESSING ARTICLES ON NONPARALLL SURFACES Filed July 13. 1928 4 Sheets-Sheet 4 WMM Jaipk Mak/Eel,

Patented Sept. 15, 1931 ROBERT L. DYAS AANI) JOSEPH MAICKEL, 0F BUTTE, MONTANA MACHINE Toor. Fon nnnsszme enfrroneson NONPARALLEL sun-FACES Applicaties ined Jury 1s, was. serial no. 292.556.

This invention relates to improvements in machine tools for dressing articles on nonparallel surfaces.vl` v Indressing articleswhich must exactly re- 5 produce one another for purposes oi' interchangeability, and which are provided with surfaces which are not parallel but mustbe dressed with exactness and nicety, it has heretofore been necessary to reset the or X- E0 ture carrying the article for the dressing' of the dierent surfaces, by hand, between the several operations. This could sometimes be accomplished automatically when the surfaces were planes at a diedral angley with 15 intersection line at a right angleto the axis of the dressing machine. When the surfaces, however, were non-parallel so that their line of intersectiondid notlie in a plane at a right angle to the axis of' the-dressing tool, ithas not been heretofore possible to automatically move and adjust the tool and article with respect to each other for securing the second operation at a predetermined relationship to the iirst. n According to the present invention, `such articles may be readily dressed in acontinL uous succession, so that'all articles will be interchangeable one with `another f as tlnall products. This result is attained by the em- 0 ployment of a dressing machine having acontinuous feeding of the articlesfto the dressing tools,^with means for automatically shifting the angle of presentation of the article to the tools, and with the provision lof tools having at their axes of rotation predetermined,anglesv operation with Irespect to each other. f On the accompanying drawings: Figure l is a transverse' section through such a' machine substantially on line l--lA of Fig. 2.

Q is a longitudinal section y,through such a machine substantially' on line 2--2 otFigl. Fig. Bis a transverse section on a larger scale of the chuclring structure. f Fig. Sai is a pla-n view correspondingfto Fig. 3. 1 I l Fig. 4 isal plan view similary to Fig. 3a, but with'the chucking members omitted for greater elearness.

' Fig. 5 isa transverse section through a sec# ond operating arbor showing its inclination and operation upon thefarticle.

. Fig. V6 is a` view similar to Fig. Ll'with the chucking table rocked in one direction. i

Fig. l7 is a view corresponding Jto/Fig. 5, but showing the inclination of the third arbor.

Fig. 8 is a View corresponding to Figs. 4 and 6, but with the chuclring table rocked in the other direction.

Fig. 9 is a section on line 9 9 of Fig. 3a.

F ig.y 10 is a'plan view of the chucking table of Fig. 9. i

ificcording to this invention, a dressing tool, here represented as of the milling type, isY provided with a ra1ne,a pair. of freely rotatable sprockets carrying a. series of links, each carrying chuclring tables for supporting the articles and gripping devices lfor holdin the articles `in position, as well aslocating an centering pins for determining the angle of presentation of the respective ohuclring tables beneath the dressing tools. The `ramefalso hasV a plurality of journal" blocks, each of which receives an arbor carrying the milling cutteror cutters for opera-tion upon the article.- Thesebloclrs carry` the arbors at re-l spectively inclined positions, as `shown in Figs. 3, 5 and 7, Vfor*operating upon. the are ticle to produce plane surfaces thereon which relatively have intersections constituting diedral angles whose lines of intersection are horizontal. By the rocking'ofthe chuclring table carrying-the article, the suraces'may furtherbe located 'outo plane with one another to form Vdiedral angles whose lines of intersection are vertical. 'By a combination of the ,angularity or inclination of the respec tive arbors, to-gether'with therocking of the chuclring tables, it is possible to dress the suriacesto-form wedging dove-tails', for ex-V ample, in the illustrated form.

The invention has been illustrated l on the accompanying drawings as amilling machine for ormingtlie wedging dove-tails of drillheads as shown inthe respective figures.-

j ln ythe drawings, a 'hollow main frame l0. is provided withan intermediate partition wall il, and the transverse braces 12' to stiften' sfr the walls with res ect to one another adjacent their tops. lso upwardly extending from this frame, being in continuation of the outer wall of the partition wallll, are the guard walls 13 and 14 having the apertured top plate 15. These walls extend only along the central portion of the frame, and guards 16 and 17 are provided to prevent accidents, as will be more clearly described hereinafter.

Freely ournaled in the frame are the drum shafts 20, 20ay having the drums 21, 21a with spaced flanges 22 thereon to support the article feeding chain. This article Vfeeding chain comprises a plurality of links 23 which are all alike, and in the illustrated form are each provided with three sets of chucking elements. Each link is provided at its lower edge with a pivot pin 24 to receive the tie links 25 which hold the operating links 23 together to form a chain. These links 23 are likewise provided at their bottoms with the oppositely skewed rack teeth 26, 27, which are preferably formed as separate members secured at the bottoni of the dove-tailed extensions 28 of the links 23 (Fig. 3).

Likewise journaled in the machine frame is a driving shaft 29 having keyed thereto driving gears 30 which have their teeth skewed to a herring-bone design so that they mesh with and drive the racks 26, 27 of the links 23. As will be seen from Fig. 2, the successive links 23 abut against each other when in the uppermost position or operating flight in engagement by their dove-tails 28 with the mating'slide members 31, 31a of the machine frame, so that the pressure from the gears 30 against the teeth of racks 26, 27 will pushthe upper line of links toward the right in Fig. 2, and beneath the operating arbors.

Each `of the individual links 23, as shown in Figs. 2 and 3, is provided with three pivots which are illustrated as vertical in position when beneath the dressing arbors, and are held in position by the cap screws 36 passing downward therethrough, in conjunctionwith the collars 37 at their lower ends of these pivots 35 is pro-vided at its upper end with a chucking table 38 which is in-v f elinedto the horizontal (Fig. 9). At the sides of the links, the chucking tables 38 Yare provided with extensions 39 having pivot members 40 to receive the angular grippingjaws 41- which each have an arcuate notchr42 facing each other and provided lwith teeth 43- to bite against and hold the article vto be dressed (Fig. 3). Thelaterally directedupper surfaces of the respect-ive gripping members are formed as cams 44 to cooperate with the pressure plates 45, as will now be described. f I Y Y Rigidly fastened opposite each dressing arbor, on the walls 13, 14 of the frame, is a pressure member comprising blocks 46, 46a

secured to the respective wall 13, 14 by cap screws 47 and having horizontal holes therethrough for the passage of the guide pins 48 which are secured at their front ends 48m in the pressure plates (Fig. 3a). A further hole 49 is provided in each of the blocks 46, 46a for the reception of the pressure spring 50, 50a, respectively, which thus bears against a thrustk plate 51 and against the pressure plate 45 and hence against the cam surfaces -44 of the gripping members 41, so that these membersare forced into position upon the article located on the chucking table 38. The bolts 48 are provided with the retaining heads 48h to prevent the projection of the plates 45 from the machine under the impetus of the springs 50, if for any reason the gripping members 41 are not located opposite the same.r

The assemblage of pressure plates 45 bolts 48 and springs 50 is repeated along the length of the frame beneath the working arbors, it being preferred to have the axis of a pair of springs 50, 50a lie in the same vertical plane Y as the axis of each of the dressing arbors.

Likewise located on the upper surfaces of the walls 13, 14 of the frame are the cam blocks 60, a, respectively, which are fixed in position by the screws 61. Each of these cam blocks has a groove 62 (Figs. 3, 4, 6 and 8), for the reception of the downwardly extending projection 63 of the locating pins 64, 64a, which are slidably mounted in holes in the upwardly extending lateral flanges 65 of the respective links 23. These holes are respectively located with their axes in the same horizontal plane, and also in vertical planes intersecting at the axis of the pivots 35, a pair of these locating pins 64. 64a being provided opposite each pivot 35. The locating pins 64, 64a are not, however, in the same straight line, but are advanced through a small angular distance in the direction of feed of the respective links 23, for example, and are formed with slots 66 therein to re ceive the securing pins 67 in the extensions 65 of the respective links 23. Each of the locating pins has a conical end 68, 68a-adapt ed to iitla conical cavity 69, 69a formed in the adjacent side of the chucking table 38 (Fig. 3). These conical cavities 69, 690l are located'with a common axial line lying in the same horizontal plane as the axis of the locating pins 64, 64a, and passing through the axis of the respective pivot 35.

The upper surface of the chucking table 38 is preferably provided with the grooves 70 kto receive the cutting edges of the drill head according to the present illustration, so that the bite of the teeth 43 of the gripping members 41 will seat the article of work firmly ron thechucking table, so that it can neither move nor rotate' withrespect thereto."

.A housing is iixedly secured to the top l76 of the frame `10, 11, which latter is proieeasei vided rwith transverse dove-tailed`rguide rails 77 (Figs .1 and2) equal in number` tothe number :of milling .arbors to .be L:provided .in the illustrated form, here three. Each of these guide rails 7 f7 .carries a kblock 78 which may benadjusted transversely of the machine by ia spindle '7 9 having collars thereon to enF gage the housingv 7 5 and threaded at. its inner end to enga-ge a threaded cavity in the block 78. Each of these .blocks 7 8is provided `With vertical guide rails 80 to receive a respective bearing block `81 which is provided With suitable rollerfbeariiigs 82 to A'carry .the arbor 83. This arbor has .a reduced rearward ex eiision 84; to receive a 1mgear 85 keyed thereto .and secured in .posi .i ii by the clamping 4nut 86 (F At the .front end the arbor has a collar 87 andthe 'reduced .portion 88 to receive one or more :milling cutters 89 (Fig. 3). A stub pin 90 of the arbor extends into a beariii-g bushing 91 carried in im enjd cap 92 hav ing slots :93 therein to receive the clamping ccreivs 94 Wmch nass into the upper `Wall 13. A :bracketi95 on the housing 75 is provided above `each of the bearing blocks 81 to receive a threaded spindle 96 having an .adjusting hand Wheel 97 v`at the upper end thereof and itseli threaded into the :hlocr 81. Cavi ies 98 are provided in the block'81 to receive the clamping bolts 99 which extend through the end Wall of the housing 75 and through 4.the several blocks 81 and their. slides; and When tightened prevent the transverse or vertical movement of the bloc-ks 81 y'but hold yall of these blocks in their pre-adjusted position.

The drive li .r the mechanism is obtained fre-mnu electrical motor M located in the base of ythe machine .and having a driving chain 100 operating a sprocket 1010i the main driv- :shaft 102 lwhich is journaled. in the :machine frame :and carries keyed theretoa gear 103 meshing With't-lie pinion 104 on the arbor driving shaft 105. The arbor driving shaft 105 has three skeW :gears 106 thereon, one opposite each of the .arbors 83 and engaging With -a skew gear 107 on the vertical driving shari 108 thenrhor, which at its upper end is provided evvith a Worm gear 109 tor mesh with the gear 85 on .the respective arbor 83. Sui-table roll-er bearings 110 are provided for the vertical shafts 108. The drives for each of Ythe arbors are alike,.and need not be shown or described greater detail. 1

. Likewise jouinaled in brackets 111 of ythe haine is the transverse jack-shaft 112 having a .skei-v gear 113 therein ldriven 'by a similar skew gear 1.14 keyed -on-the main driving shaft 102. .A Worm 115 on the jack-shaft 112 meshes Wit-h and drivesa Worin gear 116 on the secondary shaft 117, which has a. similar Worin .118 meshing with a Worin VWheel 119 on the link driving .sha-ft `29 described above.

The link drivingshaft 29 is illustrated as j having suitablero'ller bearings 29a.

It is preferred to provide the angle bars rrock arms 127 are provided prefere* 120 in the frame 10 to carry the weight oi" the links 23 in their passage on the lower iiight from lthe drinn 21 to the drum .21a (Fig. 1).

ln the present illustration, three arbors 83 are provided, Which are respectively designated 83a, 83h and 83C in Fig. rl`he anis of arbor 83a: is horizont-al so that it operates siinilailyto an ordiiiarj. l Lincoln milling machine, and produces the parallel surfaces and grooves as shoivn inr F 3. The second arbor 836 is inclined downwardly 'ovard the right in Fig. 1, as illustrated iii F ig. 7, and carries one or more milling cutters 89o which dress certain surfaces of the article on 189c'to effect a similar dressing of surfaces which are to be slightly inclined toward the left from the vertical, as slioivii in this Fig. .5.

A yoke is secured by bolts 126 to the upper portionV of the Walls and. 1li above the'druni 21, and a sha t 125 is passed across the .Guard member 17 at this Joint to su o port the rock arms 12;' carrying a pivot 128 for tie marking roll 129 Whicn'isheld depressed by a plunger 130 actuated by ka spi-Ing 131 reacting vagainst l.the yoke 125. rllie plunger 130 is extended through the yok 125 and c airiesthe adjusting nut to limit its downward movement, and therewith the downward movement oi the marking Wheel 129. The marking wheel 129 carries spaced teeth 133 for engagement by the articles passing beneath it, so that the marking Wheel 129 is moved by a given angular L...tance each time an article passes through it and during sucliinovement presents a marking tooth 13aL against the upper sur. ace ot the article whereby to mark it and indicate that the dressing has been accomplished.

v with a. counting device 135 Whose opere lin-L ger 13S` is contacted bv a tooth 133 each time the marking vmeel 129 is moved. soy that the The Vmotor lai isset in motion, whereby .l

tl'irough the yseveral gears and ivo-rms are driven the arbors 83a., 8379, ci' Fig. 2, and the link driving shaft 29 and its gears 30. Preliminary to ths,rthe clamping holts 9i and 99 will have been loosened and the spind les 7 9 and 96revolved until the respective arbois in such position that their mill'- ing cutters 89, 89o, 89o are properly located for accom ilishine; the dressing intended.

Theclamping bolts99 and 94 are then tightl ened again so that the arbors are locked invariably in such positions.

As al link 23 in itsclockwise course around the drums 21, 21a (Fig. 2) comes to the hori- Zontal position and enters into its guided relationship with the dove-tailed flanges 31, 31a of the faine walls 18, 14, it is located just beyond the upper edge of the guard 16. The clamping members 41 are still open, substantially as shown in the lower flight, Fig. 1, and the operator can now insert an unfinished article upon the chucking table 38, where it is self-alined by the inclination of this table as shown in Fig. 9. The article rests on this table during its further movement along the upper horizontal flight. An article is placed upon each of the three tables carried by a link 28. is the 80 drive the racks 2G, 2?', the links are Vforced forward along their dove-tailed guides and beneath the arbors 83a, 886, 83o, so that the tools 89, 89?), 890 on the latter operate to dress the surfaces of the articles. As a link 23 kcomes opposite the first arbor 830., the grippingplates 45 engage the cam surfaces 44 of the gripping members 41 and force these members inwardly until they bite into and seat the article firmly upon the chucking table 88. This cccurs slightly before the article cornes beneath the milling tools 89. At the same time, the downward projections 62 of the locating pins G4, 64a enter the grooves 62 of the Cain bloc-lis G0, a and are held thereby in the position shown in Fig. 4, in which the conical ends (38,

68a of these locating pins project about halfwav into the cavities G9, 69a of the chucking table 38, In this position, the chucking table has the axis of its cavities 69, 69a at a right angle to the direction of movement of the link 23, so that a milling operation is accomplished on the article at an angle to the plane a-z of its cutting edges, which is determined by the inclination of the uppersurface of the chucking table 38 9).

As the respective link 23 continues to advance toward the right in Fig. 2, and just before a chucking table 88 comes beneath the second arbor 83?), the groove 62 at either side is given an offset to the right, as shown in 6, whereby the locating pins 64 and 64a are forced toward the right, the pin 64a entering fully by its conicalend 68a into the conical cavity 6960, and causing a rotation of the chucking table 38 about its pivot 85 int-o the position shown in Fig. 6. During this time, the article has been continued in its position on the chucking table 38 by the continued engagement of the grip ping members 41 which are forced inward by the action of pressure l plates 45, the cam surfaces 44 being for this purpose preferably formed concentrically with the axis of the pivot 35.. rllhe second arbor 83?) is inclined as shown in Fig. 7, so

lthat by a combination of the rotation of the located opposite the same chucking table`38 about its axis, and the inclination of the arbor 83?; itself, certain of the surfaces dressed produce one-half of a wedgelike dove-tail. Y

Likewise, as the chucking vtable A8 approaches the third arbor 830, the cam grooves 62 are odset to the left (Fig. 8) so that the locatingpins 64, 64a are now'mov'ed toward the left until the conical end 68 of the locating pin 64. enters fully into the conical cavity 69 of the chucking table' 38, and this table has been rotated in a'counterclockwise direction to the position shownvin Fig. 8. The third arbor 830 is likewise inclined upward toward the right, as shown in Fig. 5, so that by a combination of the `rotation of the chucking ta le about its axis andthe inclination of the arbor itself, the other surfaces of the wedge-like dovetail are formed on the article.

lt will be noted that the operations thus described are repeated successively for the three chucking tables located on each link 28: and for each of the linksin turn, since each of the chucking tables has the article secured thereon individually by the pressure plates 45; and each chucking table is rotated and located individually by its individual locating pins 64, 64a; and like operations are performed upon each of the articles by the maintained relative angularities of the arbors 88a, 88?), 880.

As a respective link23 comes to the end of the dove-tailed guides 31, 31a, it enters upon the drum wheel 21 and is carried around this wheel and returned on the lower flight. The blocks46, 46a are preferably continued to a position beneath the shaft 128 of the marking wheel 129, so that the gripping mem- 1iers 41 continue to hold the articles in positionV on the chucking tables until after they have been marked. As soon as the gripping membe s 41 leave the pressure plates 45, these members drop or are forced outwardly as by the springs 41s, so that the article is now resting freely on the vchucking table 38, from which' it may be removed by an operator stationed in front of the guard member 17.

shown in Fig. 9, the surface of the chuclringtable 38 is illustrated as a plane a, a, which is inclined 'to the horizontal by the angleV snbtended between the plane a, a and the horizontal plane b. The movement of the chucking table is parallel to the horizontal plane beneath the cutting tools 89 represented in dotted lines in Fig. 9, so that the article a has its several surfaces m, n, 0 (Fig. 9) dressed horizontally, but `at the same subtended aiigleivith respect to the cutting edges.l

lt will especially be noted' that although the several arbore 83a, 88?) and 830` may be moved up and downand axially by means of the adjustment spindles 79 and 96,l yet the `driving worms'109 and worm wheels 85 remain in power for moving' these links 23 is transmit-` ted as the racks 26 and 27 on the bottom of the respective links, this power being transmitted from one link to another by compression so that it is unnecessary to have the connecting links 25 of more than the size sutcient tor maintaining the links in chain while they are not being operated upon, including their passage in the return iight.

It is obvious that the invention is not limited to the form of execution illustrated, but that it may be practiced in many ways within the scope of the appended claims.

le claim:

l. In a machine of the class described, a plurality of arbors each having a cutting tool thereon, a chucking table for the article to be dressed, means to cause said chucking table to move past the arbors in a direct-ion substantially at right angles thereto so that the tools may operate upon the articles, said arbors being located at different angles in planes transverse to the direction of movement of said table, a supporting device for said chucking table to permit a rocking'movement of the table about an axis substantially at a right angle to the direction of movement of said table and parallel to said planes,l

and means to hold said chucking table in a definite adjusted position in its passage beneath each arbor.

2. In a machine ot the class described, an arbor having a cutting tool thereon, a chucking table and means to guide the same in a rectilinear movement past said arbor, means to support said chucking tableincluding a pivot about which the chucking table may rock, and a fixed cam cooperating with the chucking table to cause it to rock at a point when the cutting tool is not engaged with the article and to hold the chucking table from rocking while the cutting tool is dressing the article.

3. In a machine of the class described, a chucking table and means to cause said table to travel in a rectilinear direction, a plurality of arbors each having a cutting tool thereon, the axes of said arbors being llocated in parallel planes respectively at a right angle to the said rectilinear direction of movement of the chucking table, the individual arbors being arranged at different angles in their respective planes with respect to said line of travel, individual means to adjust the arbors toand from the c-hucking l" table while maintaining their respective angularr positions, andto adjust the respective arbors individually in the axial direction,

and common locking means to hold allfof said arbors in the prevailing adjusted positions.

4. In a machine of the class described,- a plurality of traveling links, a pair of Wheels, connecting means between said links so that thelinkscan'travel around said wheels, means to guide thelinks for rectilinear movement in ainv operating flight between said wheels, means independent of said lWheels and located' adjacent the beginning' of the operating flight to operate upon respective links in compression? tol holdthem in position against one another during'the operating flightl and to cause the links to move around the wheels, chucks mounted upon the respective links to support Yarticles for dressing,

and an arbor mounted with` its aXis substantially parallel to the axes of the wheelsand having a` cuttingtool thereon to dress the articles on the chucks as they pass beneath the arbor.

5.` In a machine as set forth in claim 4', the

pro-visionot rackfsegments onk each of the links, said independent driving means comprising.. gear teeth engagingxsaid racks to move the same directly, said links being in abutting relationship one with another so that the'y driving. movement is. transmitted in compressioiziA from one link tothe nextr 4 6.- In a machine of the class described, a plurality of links connected -in chain, ,means toY guide said links for substantially rectilinear movement in an operating Hight, each of said links having a chuck thereon comprising gripping jaws, means to drive the chain vofllifnks continuously, pressure plates to cooperate with said chucks guided-on the frame of the machine forv movement toward and from the respective links, and springs reacting between the pressure plate and. the frame to :torce` the plate intoY .engagement with the gripping jaws so that the jaws will automatically effect the resilient clamping of an article in. the respective chuck as the chuck is moved. past the ,platev 7.- Ina mach'ne asset forth in claim. 6, and

a plurality of arbors each` having a cutting toolthereon to operate upon the article held in the' chuck, a. press-ure rplate being located opposite each of said arbors to engage and maintain the gripping jaws. in position while the article is being dressed by the said tool.

8*.5 In a machine of the class described, a feeding mechanism for articles to be dressed comprising a plurality of links connected in chain, means: to guide said links in' rectilinear movement, each of said links having a chucking table anda pivot therefor having' its axis righ-t angles to the said line of movement, the supporting surface of the chucking table b'eingdisposed'at an. angle to theline'of'movement so thatthe article is inclined With'respect to said line of movement. f

-9. In a machine ot the class described, a feeding mechanism comprising a traveling member, a. rockable chuck mounted on said traveling member for 'movement 'about an aXis'at righty angles to said line of movement, said chuck having a pair of indexing apertures therein directed radially with respect to such pivot, said yapertures being diametrally opposite eachother. and a pair of slidable indexing fingers moving in apertures on a fixed part of the traveling member, said iingers sliding radially with respect to said pivot but not in the same diametrical plane therethrough, and means on the machine frame to cause said lingers to make respective sliding movements at predetermined intervals, whereby to cause said chuck to rock about its pivot, and to secure the chuck in such rocked position.

10. In a machine of the class described, aplurality of traveling links connected to form an endless belt, means to guide said links for rectilinear movement in an operating flight. each of said linkshaving a pair of oppositely skewed racks thereon. anddriving means for the belt located vadiacent the beginning of the operating ight including a shaft having or positelv cut skew gears to mesh with the racks of the respective links T.vhereby to drive the link Whose racks are in mesh directly and to drive preceding links b v'compression from link to link` and a plurality of arbors having cutting tools thereon to operate upon articles supported on said links. said arbors being located opposite the links in compression so that the cutting tools will operate onlv upon articles supported on links in compression.

11. In a machine of the class described. a frame having rectilinear .guide means there*- on. a traveling member movable along said guide means.y a chuck adapted to rock about a pivot at right angles to the ldirection of movement of the traveling member. means on the frame'to rock said chuck through pre determined angles at predetermined times and to hold said chuck against movement eX- cept at the time of such rocking.,v andmeans to move said traveling member. Y

12.l Machine as in claim 11', in Which the chuck has a VWork supporting surface inclined With respect to the direction of movement, and a plurality of arbors each having a cutting tool thereon and each located in a respective plane at a right angle to the direction of movement of said traveling member, the angles of the respective arbors being difg ferentwith respect to such line of movement, said frame means orrocking the chuck being soV constructed and arranged as to rock the chuck in one direction after it has left the first arbor and in the other direction after it has left the second arbor, so that the respectures. ROBERT L. DYAS.

JOSEPH MAICKEL. 

